London has one of the largest concentrations of universities and higher education institutions in the world. It has 40 higher education institutions (not counting foreign Universities with London branches) and has a student population of more than 400,000. Among the institutions in London are some of the old and world-famous colleges that today make up the federal University of London, modern universities, as well as a number of smaller and often highly specialised universities and colleges. Additionally, over 45,000 students in over 180 countries follow the University of London External System, established in 1858.